Answer:
The third side is 3√6 units.
Step-by-step explanation:
Given that this is a 90° triangle so you can apply Pythagoras Theorem :
[tex] {a}^{2} + {b}^{2} = {c}^{2} [/tex]
[tex] {a}^{2} = {c}^{2} - {b}^{2} [/tex]
[tex] {a}^{2} = {( \sqrt{90}) }^{2} - {6}^{2} [/tex]
[tex] {a}^{2} = 90 - 36[/tex]
[tex] {a}^{2} = 54[/tex]
[tex]a = \sqrt{54} = \sqrt{9 \times 6} = 3 \sqrt{6} [/tex]
